Current heat pipe structures have several disadvantages: they are generally too big (>2-3 mm in minimum dimension); they are not typically designed to provide a structural function (typically made out of hollow copper or aluminum annealed for good thermal property); and they are constructed with non-optimal cross sections for wide insertion into conformal applications. Typical cross sections include circular or square, but never <1 mm thick and >10 cm wide.
Heat transfer in consumer electronics, avionics, or satellite electronics, for example, and other known heat transfer applications, requires an efficient and scalable means. For example, as the operational speed of electronic components increases and their size decreases the need for a compact efficient means of heat removal is essential. Marked reduction in device junction temperatures as well as the spread in device temperatures is key to improving system performance and reliability. Thus, as microelectronic system power densities and performance requirements continue to increase, thermal management continues to present significant performance and design barriers. Although current PWB technology provides excellent electrical interconnectivity and controlled impedance RF lines, it presents significant thermal performance and CTE mismatch limitations. Current heat pipes have the ability to transfer large amounts of heat but are thermally distant from the heat sources. Further, in other applications such as space bound electronics, not only is size critical, but also weight.
Not only the specific electronics fields above, but also many other electronic and non-electronic related areas, face similar issues, and more, in applying conventional heat pipe technology.
Thus, several long-felt needs exist. What is needed is a way to enable robust heat spreading structures by imparting not only a thermal function (via heat transport through the vapor) but also a structural function. Further, what is needed is a mechanically efficient, lightweight structure that can be handled during manufacture, and can survive high-g shock during use in a range of demanding applications. Also, what is needed is fabrication using a flexible method that enables comformability, net-shape manufacture, and spatial adjustment of the wick density and vapor chamber geometry to optimize thermal transfer.